You can easily test the hypothesis with a little data information. Hypothesis tests of single population means are performed according to the z and t distributions. This app supports English and Korean. The test can be selected by selecting 90%, 95%, or 99% confidence intervals. When testing, you can check the graph. Have fun hypothesis testing. z-distribution and t-distribution data are stored in SQLite and are automatically checked during the test. This app can be used both when you know the average, standard deviation, the number of data and how to enter the actual sample data directly.